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Résultats 3721-3730 de 4,924
Economics of death and dying: a critical evaluation of environmental damages and healthcare reforms across the globe
2019
Batool, Rubeena | Zaman, Khalid | Khurshid, Muhammad Adnan | Sheikh, Salman Masood | Aamir, Alamzeb | Shoukry, Alaa Mohamd | Sharkawy, Mohamed A. | Aldeek, Fares | Khader, Jameel | Gani, Showkat
The economics of death and dying highlighted that environmental factors negatively influence healthcare sustainability. Therefore, this study conducted a system-based literature review to identify the negative externality of environmental damages on global healthcare reforms. Based on 42 peer-reviewed papers in the field of healthcare reforms and 12 papers in the field of environmental hazards, we identified 25 factors associated with death and dying and 15 factors associated with health-related damages across the world respectively. We noted that environmental factors are largely responsible to affect healthcare sustainability reforms by associating with the number of healthcare diseases pertaining to air pollutants. The study suggests healthcare practitioners and environmentalists to devise long-term sustainable healthcare policies by limiting highly toxic air pollutants through technology-embodied green healthcare infrastructure to attained efficient global healthcare recovery.
Afficher plus [+] Moins [-]Effect of installed capacity size on environmental efficiency across 528 thermal power stations in North China
2019
Wu, Chao | Oh, Keunyeob | Long, Xingle | Zhang, Jing
Thermal power plants are the main source of carbon dioxide emissions in China. Beijing-Tianjin-Hebei and their neighborhood provinces are the most polluted regions in China. Environmental efficiencies of 528 thermal power plants were evaluated through metafrontier epsilon-based measure, which aimed to overcome the invalid inferences of radial or non-radial model. We also analyzed the heterogeneity of environmental efficiency across different regions by considering environmental technology differences. Bootstrap regression was used in order to testify three different hypotheses to address the disadvantages of conventional regression. We found that environmental efficiency in Beijing and Tianjin is higher than the other regions and is becoming divergent. In addition, coal consumption intensity negatively affects environmental efficiency. Large-scale power stations are more environmental efficient than smaller ones. Longer equipment utilization hour can enhance energy performance of power stations, which can decrease carbon emissions and increase environmental efficiency. It is better to promote technology transfer from regions with higher environmental efficiency to regions with lower environmental efficiency. Low-carbon technologies should be promoted to decrease carbon emissions.
Afficher plus [+] Moins [-]The impact of humic acid on toxicity of individual herbicides and their mixtures to aquatic macrophytes
2019
Mihajlović, Varja | Tomić, Tanja | Tubić, Aleksandra | Molnar Jazić, Jelena | Ivančev Tumbas, Ivana | Šunjka, Dragana | Lazić, Sanja | Teodorović, Ivana
This study investigates the impact of humic acid (HA) on the toxicity of selected herbicides and their binary mixtures to aquatic plants. The focus was on two auxin simulators (2,4-D and dicamba) and two photosynthetic inhibitors (atrazine and isoproturon). The results suggested that the addition of HA to the standard synthetic medium does not affect Lemna minor growth nor the toxicity of atrazine, but increases the toxicity of 2,4-D and the binary mixture of atrazine and 2,4-D. The addition of HA to the standard synthetic medium reversibly decreased the growth (biomass) of Myriophyllum aquaticum and enhanced the toxicity of individually tested herbicides (isoproturon and dicamba) as well as their binary mixture. The results showed delayed toxic effects of auxin simulators, especially 2,4-D in the Lemna test. The recovery after the exposure to individual photosystem II inhibitors (atrazine and isoproturon) is fast in both plant species, regardless of the presence of HA. In the case of selected mixtures (atrazine + 2,4-D and isoproturon + dicamba), recovery of both plant species was noted, while the efficiency depended on the herbicide concentration in the mixture rather than the presence or absence of HA.
Afficher plus [+] Moins [-]Meltwater hydrochemistry at four glacial catchments in the headwater of Indus River
2019
Zhang, Fan | Qaiser, Faizan-ur-Rehman | Zeng, Chen | Pant, Ramesh Raj | Wang, Guanxing | Zhang, Hongbo | Chen, Deliang
Glacier runoff shows significant change under global warming in the headwater region of the Indus River with great impact on its highly populated downstream area, but the hydrochemistry characteristics of meltwater and the changing mechanism remain unclear in this region. In this study, runoff water samples were collected during May and June, 2015, from four glacial catchments in the Upper Indus Basin to investigate general characteristics and daytime dynamics of meltwater runoff together with sediment and chemical contents. Results showed that glacier runoff in the studied area had an alkaline pH and much higher sediment yields than the local average of the non-glacier areas. The carbonate-dominated geological feature in the four catchments resulted in single chemical facies of Ca–HCO₃. The dominant process determining the glacier runoff chemistry was rock-water interaction, with less soluble minerals and less intensive evaporate weathering in the Passu and Gulmit catchments than the B&B and Hinarchi catchments. Comparing the investigated catchments, the larger glacier with longer flow path exhibited higher runoff but lower melting rate, higher SSC resulting from higher erosive power of flow, and higher solute concentrations as a consequence of more intensive contact of meltwater with rock minerals along the longer flow path. For individual catchments, a negative correlation between TDS and flow rate (R² = 0.26~0.53) and changing trends of ion ratios with flow rate demonstrated that under intensive melting conditions, rock-water interactions were reduced, resulting in dilution of solutes. Overall, the general chemical characteristics of the investigated glacier runoff indicated geological control, whereas individual glacier illustrated hydrological control on the daytime dynamics of glacier runoff chemistry. The presence of glacier terminal lake and agriculture land can significantly alter the hydrochemistry of downstream runoff.
Afficher plus [+] Moins [-]Cadmium phytoextraction from contaminated paddy soil as influenced by EDTA and Si fertilizer
2019
Zhang, Pengbo | Zhao, Dandan | Liu, Yuqiao | Zhang, Yangzhu | Wei, Xiao | Xu, Bo | Bocharnikova, Elena | Matichenkov, Vladimir
The efficiency of heavy metal (HM) phytoextraction from contaminated soil directly depends on the pollutant bioavailability, which can be increased by some soil amendments. In field test, the impacts of soil-applied ethylenediaminetetraacetic acid (EDTA) and amorphous silicon dioxide (ASD) and foliar-applied monosilicic acid (MS) on cadmium (Cd) uptake by rice plants from contaminated paddy soil were investigated. Without EDTA, the solid or liquid Si materials reduced the Cd accumulation in the aboveground part of rice by 26 to 52%. If EDTA was applied, the Cd accumulation by plants was increased by 60 to 92%; however, the biomass was reduced by 16 to 35%. The combined application of Si-rich materials and EDTA provided enhanced plant tolerance to a negative influence of EDTA, while kept high Cd content in the rice stems and leaves. As a result, the Cd amounts extracted by the stems and leaves from the unit area of contaminated paddy soil were greater by 25 and 37% in comparison with those for only EDTA treatment.
Afficher plus [+] Moins [-]Comprehensive evaluation of ecological compensation effect in the Xiaohong River Basin, China
2019
Meng, Yu | Liu, Meng | Guan, Xinjian | Liu, Wenkang
Due to the complexity of ecological compensation standards and methods, some problems cannot be expected before compensation, but the evaluation of eco-compensation effect can feedback the implementation effect of eco-compensation policies and provide reference for the improvement of eco-compensation policies. This paper constructed a comprehensive evaluation index system of eco-compensation, which covered social and economic development, pollution discharge and monitoring, and pollution treatment aspects. An eco-compensation comprehensive evaluation model was established, which consisted of the projection pursuit model (PP model) and the chaotic particle swarm optimization algorithm (CPSO algorithm). The Xiaohong River Basin in China was selected as a case study. Before and after the implementation of eco-compensation policy, the compensation effects in the four counties in the basin from 2008 to 2015 were evaluated. The results showed that through the implementation of the basin eco-compensation policies, the comprehensive indicators in the four counties showed an upward trend, which indicated that the eco-compensation of the basin had achieved certain effects. Among them, Xincai was the best, and could provide reference for other counties. The research results can provide new ideas and new methods for the evaluation of eco-compensation effects.
Afficher plus [+] Moins [-]Removal of U(VI) by sugar-based magnetic pseudo–graphene oxide and its application to authentic groundwater using electromagnetic system
2019
Choi, Yu-Lim | Choi, Jong-Soo | Lingamdinne, Lakshmi Prasanna | Chang, Yoon-Young | Koduru, Janardhan Reddy | Ha, Jeong-Hyub | Yang, Jae-Kyu
Uranium U(VI) is toxic even at trace levels in aqueous solution and has adverse impacts on the health of human beings. In this study, a sugar-based magnetic pseudo–graphene oxide (SMGO) composite was prepared for the removal of U(VI) from groundwater by graphitization of sugar and ozonation, as well as synthesis with nano-size magnetite particles. To investigate the applicability of SMGO, U(VI)-spiked groundwater as well as U(VI)-contaminated groundwater samples were used in electromagnetic system. The pH-edge adsorption results suggest that adsorption occurs via an inner-sphere surface complex with an optimized pH of 4, where UO₂²⁺ is the dominant U(VI) species. The adsorption isotherm results confirmed that the adsorption of U(VI) onto SMGO occurred via a monolayer process on the homogeneous surface of SMGO and the maximum removal capacity of U(VI) was 28.2 mg/g. The high-gradient magnetic separation (HGMS) principle was applied to U(VI) removal using SMGO to facilitate recovery and the repeated use of the adsorbent during multiple batch cycles. The results indicated that the initial U(VI) concentration (439.1 μg/L) was reduced to a value less than the standard level of U(VI) for drinking water (30 μg/L) during six batch cycles and the separation efficiency was 95.2%. As such, SMGO and electromagnetic system using the HGMS principle are promising technologies for the removal of U(VI) in groundwater.
Afficher plus [+] Moins [-]Transformation of phosphorus and stabilization of heavy metals during sewage sludge incineration: the effect of suitable additives and temperatures
2019
Li, Rundong | Teng, Wenchao | Li, Yanlong | Yin, Jing | Zhang, Ziheng
Phosphorus (P), an irreplaceable nutrient for all living organisms, is facing scarcity via phosphate resources. In this research, the effect of suitable additives and temperature on P and heavy metals speciation during sewage sludge (SS) thermochemical treatment was investigated. The results demonstrated that additives (CaO and MgO) could promote the conversion of non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP). X-ray diffraction measurements indicated that the phosphorus mineral phase in sewage sludge ash (SSA) mainly was AP, with addition of MgO and CaO. Moreover, orthogonal testing revealed that the optimal molar ratio of Mg:Ca:P for P recovery as AP was 1:3.5:1 at 750 °C. Risk index results implied that the heavy metals in the phosphorus-enriched SSA have low potential ecological risk. Thermodynamic equilibrium calculations revealed that P reacted with the other metal ions was in the following order: Ca²⁺ > Mg²⁺ > Al³⁺ > Fe³⁺ > Zn²⁺ > K⁺. Graphical Abstract
Afficher plus [+] Moins [-]Watershed scale patterns in steroid hormones composition and content characters at a typical eutrophic lake in southeastern China
2019
Zhang, Fengsong | Yu, Qibiao | Yang, Linsheng
Natural steroid hormones in the aquatic environment have attracted increasing attention because of their strong endocrine disrupting potency. Seven steroid hormones (estrone, 17α-estradiol, 17β-estradiol, estriol, testosterone, androstenedione, and progesterone) were analyzed from surface water and sediment sampled from Chaohu Lake, its upstream rivers (the Hangbu River, Nanfei River, Shiwuli River, and Pai River), drainage from the adjacent farmland, and treated and untreated municipal sewage. Concentrations of the seven target steroid hormones ranged from below the detection limit (ND) to 69.5 ng L⁻¹ in the water of Chaohu Lake and the upstream rivers. Three steroids—estrone, estriol, and 17α-estradiol—were found in relatively high residual concentrations in the water, with maximum concentrations of 69.5 ng L⁻¹, 51.5 ng L⁻¹, and 23.3 ng L⁻¹, respectively. All of the target steroid hormones except estriol were detected in the sediment in concentrations of ND–16344 ng kg⁻¹. The dominant steroid hormone in the sediment of Chaohu Lake and the upstream rivers was 17α-estradiol. In the Shiwuli River and the Pai River, the dominant steroid hormones (estrone and estriol) were the same as those in the untreated municipal sewage. This confirmed the deduction that untreated municipal sewage was the major source of steroid hormone residues in these two rivers. The main steroid hormone in the water of the Hangbu River and Chaohu Lake was 17α-estradiol, the same as that in the farmland drainage. In addition, 17α-estradiol was verified as the major factor in the contribution of farmland drainage to the pollution in these rivers. The water in the Nanfei River had high concentrations of estriol and 17α-estradiol. This indicates that both untreated municipal sewage and farmland drainage were the major sources. The discharge of steroid hormones from the four rivers to Chaohu Lake was approximately 75.1 kg year⁻¹, with the highest contributor being 17α-estradiol (24 kg year⁻¹). Therefore, based on the results of this study, the farmland drainage should be controlled to reduce the steroid hormone pollution in Chaohu Lake.
Afficher plus [+] Moins [-]Aerosol and pollutant characteristics in Delhi during a winter research campaign
2019
Dumka, Umesh C. | Tiwari, Suresh | Kaskaoutis, Dimitris G. | Soni, Vijay K. | Safai, Promod D. | Attri, Shiv D.
Urban areas in developing countries are major sources of carbonaceous aerosols and air pollutants, pointing out the need for a detailed assessment of their levels and origin close to the source. A multi-instrument research campaign was performed in Delhi during December 2015–February 2016 aimed at exploring the pollution levels and the contribution of various sources to particulate matter (PM) concentrations, black carbon (BC) aerosols, and trace gases. The weak winds (< 5–6 m s⁻¹) along with the shallow boundary layer favoured the formation of thick and persistent fog conditions, which along with the high BC (24.4 ± 12.2 μg m⁻³) concentrations lead to the formation of smog. Very high pollution levels were recorded during the campaign, with mean PM₁₀, PM₂.₅, CO, NO, and O₃ concentrations of 245.5 ± 109.8 μg m⁻³, 145.5 ± 69.5 μg m⁻³, 1.7 ± 0.5 ppm, 7.9 ± 2.3 ppb, and 31.3 ± 18.4 ppb, respectively. This study focuses on examining the daily/diurnal cycles of the aerosol optical properties (extinction, scattering, absorption coefficients, single scattering albedo), as well as of PM and other pollutant concentrations, along with changes in meteorology (mixing-layer height and wind speed). In addition, the hot-spot pollution sources in the greater Delhi area were determined via bivariate plots and conditional bivariate probability function (CBPF), while the distant sources were examined via the concentration weighted trajectory (CWT) analysis. The results show that the highest aerosol absorption and scattering coefficients, PM, and trace gas concentrations are detected for weak winds (< 2 m s⁻¹) with a preference for eastern directions, revealing high contribution from local sources and accumulation of pollutants within urban Delhi.
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